Wetting Envelope

The importance of selecting the right adhesive for non-porous plastic substrates, emphasizing the role of wetting in bond strength. Wetting refers to how well an adhesive spreads across a surface, influenced by the substrate’s surface energy and the adhesive’s surface tension. A wetting envelope is introduced as a tool to visualize the suitability of various adhesives for specific substrates by graphing their polar and dispersive forces. It highlights that lower polarity substrates, commonly used in the automotive industry, require lower polarity adhesives for effective bonding. Additionally, surface treatments like cleaning or plasma treatment can modify substrate polarity to improve adhesive bonding. It underscores the significance of timely bonding post-treatment due to the temporary nature of treatment effects.